From what I am able to grasp so far......
You can have some of both. Someone suggested a 36v motor built for torque
run on 48v ( check if the manufacteror will warranty on 48v).
Makes sense to me. 33% more rpms. Someone please correct me if I'm wrong here, 480 non-programable curtis will run this thing well enough for most applications.
But if you are looking for a street racer that will mountain climb, It may not happen. Kinda like do want the 4x or cuda?
The motor you showed says it is a speed motor with 10% torque loss running on 48v.....

Yes, that's what I was thinking also. But according to Alltrax, if you up the amperage capability of the controller , to say 650 amps, you recover enough of the lost torque from using the speed motor, and actually realize a 30% gain in torque.

You probably need to ask Nate about this one. But from what I hear....The controller is a valve. It like the faucet on a hose. U can't get more water out of the hose by simply putting a larger faucet on it. Unless the faucet is restricting the flow. If the input ( Battery Pack) is not increased then there is just x amount of amps available . So that if all amps are available thru a 450 amp controller - going to a 700 amp controller will give no gain. Nathan?

36v 275amp stock E-Z-Go Fleet. Upgraded to the Alltrax 400amp Programmable, saw a nice bump in torque, speed was the same.
Upgraded to 48v saw another bump in torque, and a big speed increase, still on same motor. I figure my next step is a higher RPM motor.

Gorno, thanks man. Thats's the good stuff, right there.
That is exactly the kind of info we are needing!
Tells me the 275A controller was not a big enough faucet.
36v motor on 48v turns . what? 33% more rpms? so a 3000rpm motor turns @4500rpms = more speed and with 33% more volts = more torque, Right?
So now, if you go to a new motor what voltage, hp, and rpm are you going to select?
The Q nagging me is would a 36v motor on 48v be snappier than a 48v motor?
Thanks for your input!